target: pass sense_reason as a return value
Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values. This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.
(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
sense_reason_t with Roland's MODE SELECT changes)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index c4c931b..98044bf 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -557,7 +557,8 @@
{
struct se_cmd *cmd = container_of(work, struct se_cmd, work);
- transport_generic_request_failure(cmd);
+ transport_generic_request_failure(cmd,
+ TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
}
/*
@@ -625,7 +626,6 @@
complete(&cmd->t_transport_stop_comp);
return;
} else if (cmd->transport_state & CMD_T_FAILED) {
- cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
INIT_WORK(&cmd->work, target_complete_failure_work);
} else {
INIT_WORK(&cmd->work, target_complete_ok_work);
@@ -976,7 +976,8 @@
}
EXPORT_SYMBOL(transport_set_vpd_ident);
-int target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
+sense_reason_t
+target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
{
struct se_device *dev = cmd->se_dev;
@@ -991,7 +992,7 @@
if (cmd->data_direction == DMA_TO_DEVICE) {
pr_err("Rejecting underflow/overflow"
" WRITE data\n");
- goto out_invalid_cdb_field;
+ return TCM_INVALID_CDB_FIELD;
}
/*
* Reject READ_* or WRITE_* with overflow/underflow for
@@ -1002,7 +1003,7 @@
" CDB on non 512-byte sector setup subsystem"
" plugin: %s\n", dev->transport->name);
/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
- goto out_invalid_cdb_field;
+ return TCM_INVALID_CDB_FIELD;
}
/*
* For the overflow case keep the existing fabric provided
@@ -1022,10 +1023,6 @@
return 0;
-out_invalid_cdb_field:
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
- return -EINVAL;
}
/*
@@ -1065,7 +1062,8 @@
}
EXPORT_SYMBOL(transport_init_se_cmd);
-static int transport_check_alloc_task_attr(struct se_cmd *cmd)
+static sense_reason_t
+transport_check_alloc_task_attr(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
@@ -1079,7 +1077,7 @@
if (cmd->sam_task_attr == MSG_ACA_TAG) {
pr_debug("SAM Task Attribute ACA"
" emulation is not supported\n");
- return -EINVAL;
+ return TCM_INVALID_CDB_FIELD;
}
/*
* Used to determine when ORDERED commands should go from
@@ -1093,17 +1091,12 @@
return 0;
}
-/* target_setup_cmd_from_cdb():
- *
- * Called from fabric RX Thread.
- */
-int target_setup_cmd_from_cdb(
- struct se_cmd *cmd,
- unsigned char *cdb)
+sense_reason_t
+target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
{
struct se_device *dev = cmd->se_dev;
unsigned long flags;
- int ret;
+ sense_reason_t ret;
/*
* Ensure that the received CDB is less than the max (252 + 8) bytes
@@ -1113,9 +1106,7 @@
pr_err("Received SCSI CDB with command_size: %d that"
" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
- return -EINVAL;
+ return TCM_INVALID_CDB_FIELD;
}
/*
* If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
@@ -1130,10 +1121,7 @@
" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
scsi_command_size(cdb),
(unsigned long)sizeof(cmd->__t_task_cdb));
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason =
- TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- return -ENOMEM;
+ return TCM_OUT_OF_RESOURCES;
}
} else
cmd->t_task_cdb = &cmd->__t_task_cdb[0];
@@ -1145,50 +1133,30 @@
/*
* Check for an existing UNIT ATTENTION condition
*/
- if (core_scsi3_ua_check(cmd, cdb) < 0) {
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION;
- return -EINVAL;
- }
+ ret = target_scsi3_ua_check(cmd);
+ if (ret)
+ return ret;
ret = target_alua_state_check(cmd);
- if (ret) {
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- if (ret > 0)
- cmd->scsi_sense_reason = TCM_CHECK_CONDITION_NOT_READY;
- else
- cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
- return -EINVAL;
- }
-
- /*
- * Check status for SPC-3 Persistent Reservations
- */
- ret = target_check_reservation(cmd);
- if (ret) {
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
- cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
- cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
+ if (ret)
return ret;
- }
+
+ ret = target_check_reservation(cmd);
+ if (ret)
+ return ret;
ret = dev->transport->parse_cdb(cmd);
- if (ret < 0)
+ if (ret)
+ return ret;
+
+ ret = transport_check_alloc_task_attr(cmd);
+ if (ret)
return ret;
spin_lock_irqsave(&cmd->t_state_lock, flags);
cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
- /*
- * Check for SAM Task Attribute Emulation
- */
- if (transport_check_alloc_task_attr(cmd) < 0) {
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
- return -EINVAL;
- }
spin_lock(&cmd->se_lun->lun_sep_lock);
if (cmd->se_lun->lun_sep)
cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
@@ -1204,7 +1172,7 @@
int transport_handle_cdb_direct(
struct se_cmd *cmd)
{
- int ret;
+ sense_reason_t ret;
if (!cmd->se_lun) {
dump_stack();
@@ -1234,13 +1202,41 @@
* and call transport_generic_request_failure() if necessary..
*/
ret = transport_generic_new_cmd(cmd);
- if (ret < 0)
- transport_generic_request_failure(cmd);
-
+ if (ret)
+ transport_generic_request_failure(cmd, ret);
return 0;
}
EXPORT_SYMBOL(transport_handle_cdb_direct);
+static sense_reason_t
+transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
+ u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
+{
+ if (!sgl || !sgl_count)
+ return 0;
+
+ /*
+ * Reject SCSI data overflow with map_mem_to_cmd() as incoming
+ * scatterlists already have been set to follow what the fabric
+ * passes for the original expected data transfer length.
+ */
+ if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
+ pr_warn("Rejecting SCSI DATA overflow for fabric using"
+ " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
+ return TCM_INVALID_CDB_FIELD;
+ }
+
+ cmd->t_data_sg = sgl;
+ cmd->t_data_nents = sgl_count;
+
+ if (sgl_bidi && sgl_bidi_count) {
+ cmd->t_bidi_data_sg = sgl_bidi;
+ cmd->t_bidi_data_nents = sgl_bidi_count;
+ }
+ cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
+ return 0;
+}
+
/*
* target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
* se_cmd + use pre-allocated SGL memory.
@@ -1273,7 +1269,8 @@
struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
{
struct se_portal_group *se_tpg;
- int rc;
+ sense_reason_t rc;
+ int ret;
se_tpg = se_sess->se_tpg;
BUG_ON(!se_tpg);
@@ -1294,9 +1291,9 @@
* for fabrics using TARGET_SCF_ACK_KREF that expect a second
* kref_put() to happen during fabric packet acknowledgement.
*/
- rc = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
- if (rc)
- return rc;
+ ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
+ if (ret)
+ return ret;
/*
* Signal bidirectional data payloads to target-core
*/
@@ -1305,16 +1302,16 @@
/*
* Locate se_lun pointer and attach it to struct se_cmd
*/
- if (transport_lookup_cmd_lun(se_cmd, unpacked_lun) < 0) {
- transport_send_check_condition_and_sense(se_cmd,
- se_cmd->scsi_sense_reason, 0);
+ rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
+ if (rc) {
+ transport_send_check_condition_and_sense(se_cmd, rc, 0);
target_put_sess_cmd(se_sess, se_cmd);
return 0;
}
rc = target_setup_cmd_from_cdb(se_cmd, cdb);
if (rc != 0) {
- transport_generic_request_failure(se_cmd);
+ transport_generic_request_failure(se_cmd, rc);
return 0;
}
/*
@@ -1349,7 +1346,7 @@
rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
sgl_bidi, sgl_bidi_count);
if (rc != 0) {
- transport_generic_request_failure(se_cmd);
+ transport_generic_request_failure(se_cmd, rc);
return 0;
}
}
@@ -1495,16 +1492,17 @@
/*
* Handle SAM-esque emulation for generic transport request failures.
*/
-void transport_generic_request_failure(struct se_cmd *cmd)
+void transport_generic_request_failure(struct se_cmd *cmd,
+ sense_reason_t sense_reason)
{
int ret = 0;
pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
cmd->t_task_cdb[0]);
- pr_debug("-----[ i_state: %d t_state: %d scsi_sense_reason: %d\n",
+ pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
cmd->se_tfo->get_cmd_state(cmd),
- cmd->t_state, cmd->scsi_sense_reason);
+ cmd->t_state, sense_reason);
pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
(cmd->transport_state & CMD_T_ACTIVE) != 0,
(cmd->transport_state & CMD_T_STOP) != 0,
@@ -1515,7 +1513,7 @@
*/
transport_complete_task_attr(cmd);
- switch (cmd->scsi_sense_reason) {
+ switch (sense_reason) {
case TCM_NON_EXISTENT_LUN:
case TCM_UNSUPPORTED_SCSI_OPCODE:
case TCM_INVALID_CDB_FIELD:
@@ -1528,6 +1526,9 @@
case TCM_CHECK_CONDITION_UNIT_ATTENTION:
case TCM_CHECK_CONDITION_NOT_READY:
break;
+ case TCM_OUT_OF_RESOURCES:
+ sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+ break;
case TCM_RESERVATION_CONFLICT:
/*
* No SENSE Data payload for this case, set SCSI Status
@@ -1555,13 +1556,12 @@
goto check_stop;
default:
pr_err("Unknown transport error for CDB 0x%02x: %d\n",
- cmd->t_task_cdb[0], cmd->scsi_sense_reason);
- cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
+ cmd->t_task_cdb[0], sense_reason);
+ sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
break;
}
- ret = transport_send_check_condition_and_sense(cmd,
- cmd->scsi_sense_reason, 0);
+ ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
@@ -1579,21 +1579,21 @@
static void __target_execute_cmd(struct se_cmd *cmd)
{
- int error = 0;
+ sense_reason_t ret;
spin_lock_irq(&cmd->t_state_lock);
cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
spin_unlock_irq(&cmd->t_state_lock);
- if (cmd->execute_cmd)
- error = cmd->execute_cmd(cmd);
+ if (cmd->execute_cmd) {
+ ret = cmd->execute_cmd(cmd);
+ if (ret) {
+ spin_lock_irq(&cmd->t_state_lock);
+ cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
+ spin_unlock_irq(&cmd->t_state_lock);
- if (error) {
- spin_lock_irq(&cmd->t_state_lock);
- cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
- spin_unlock_irq(&cmd->t_state_lock);
-
- transport_generic_request_failure(cmd);
+ transport_generic_request_failure(cmd, ret);
+ }
}
}
@@ -1987,53 +1987,6 @@
spin_unlock_irqrestore(&cmd->t_state_lock, flags);
}
-/*
- * transport_generic_map_mem_to_cmd - Use fabric-alloced pages instead of
- * allocating in the core.
- * @cmd: Associated se_cmd descriptor
- * @mem: SGL style memory for TCM WRITE / READ
- * @sg_mem_num: Number of SGL elements
- * @mem_bidi_in: SGL style memory for TCM BIDI READ
- * @sg_mem_bidi_num: Number of BIDI READ SGL elements
- *
- * Return: nonzero return cmd was rejected for -ENOMEM or inproper usage
- * of parameters.
- */
-int transport_generic_map_mem_to_cmd(
- struct se_cmd *cmd,
- struct scatterlist *sgl,
- u32 sgl_count,
- struct scatterlist *sgl_bidi,
- u32 sgl_bidi_count)
-{
- if (!sgl || !sgl_count)
- return 0;
-
- /*
- * Reject SCSI data overflow with map_mem_to_cmd() as incoming
- * scatterlists already have been set to follow what the fabric
- * passes for the original expected data transfer length.
- */
- if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
- pr_warn("Rejecting SCSI DATA overflow for fabric using"
- " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
- return -EINVAL;
- }
-
- cmd->t_data_sg = sgl;
- cmd->t_data_nents = sgl_count;
-
- if (sgl_bidi && sgl_bidi_count) {
- cmd->t_bidi_data_sg = sgl_bidi;
- cmd->t_bidi_data_nents = sgl_bidi_count;
- }
- cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
- return 0;
-}
-EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);
-
void *transport_kmap_data_sg(struct se_cmd *cmd)
{
struct scatterlist *sg = cmd->t_data_sg;
@@ -2054,10 +2007,8 @@
/* >1 page. use vmap */
pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
- if (!pages) {
- cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+ if (!pages)
return NULL;
- }
/* convert sg[] to pages[] */
for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
@@ -2066,10 +2017,8 @@
cmd->t_data_vmap = vmap(pages, cmd->t_data_nents, VM_MAP, PAGE_KERNEL);
kfree(pages);
- if (!cmd->t_data_vmap) {
- cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+ if (!cmd->t_data_vmap)
return NULL;
- }
return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
}
@@ -2135,7 +2084,8 @@
* might not have the payload yet, so notify the fabric via a call to
* ->write_pending instead. Otherwise place it on the execution queue.
*/
-int transport_generic_new_cmd(struct se_cmd *cmd)
+sense_reason_t
+transport_generic_new_cmd(struct se_cmd *cmd)
{
int ret = 0;
@@ -2148,7 +2098,7 @@
cmd->data_length) {
ret = transport_generic_get_mem(cmd);
if (ret < 0)
- goto out_fail;
+ return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
atomic_inc(&cmd->t_fe_count);
@@ -2174,14 +2124,11 @@
if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
- if (ret < 0)
- return ret;
- return 1;
+ /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
+ WARN_ON(ret);
-out_fail:
- cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
- cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- return -EINVAL;
+ return 0;
+
queue_full:
pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
@@ -2625,10 +2572,9 @@
return 0;
}
-int transport_send_check_condition_and_sense(
- struct se_cmd *cmd,
- u8 reason,
- int from_transport)
+int
+transport_send_check_condition_and_sense(struct se_cmd *cmd,
+ sense_reason_t reason, int from_transport)
{
unsigned char *buffer = cmd->sense_buffer;
unsigned long flags;